Another heat pump question

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#3099761 4-Jul-2023 17:32

Handle9: Design conditions for Auckland are typically a low of 5 degrees in a high performance building but it also depends on your internal target temperature. From memory the ASHRAE extreme low temperature is 1.8 dry bulb. That’s not very cold.

“Vested interests” are the supply chain. The reality of construction, as opposed to a fairy tale that everything can change over night, is that you can’t change the availability of building products instantly. You certainly can’t quickly change construction methods. The industry tried that in the mid 90s and it created the leaky homes crisis.

The minimum requirements are different from Southland to Northland, particularly for windows, so if builders are building to the same minimum requirements they aren’t complying.

the main difference between north and south was basically a layer of ceiling insulation, thats all. thats a common upgrade done here as its pretty cheap. so they where complying wit the rules, its just the rules sucked. hence the big change. nz is few generations behind everyone else.

the vested interest is people want to making money from housing. so its a case of lets make it look fancy as possible and skimp on everything else. the average length of home ownership in nz is now only 5 years. there is no ROI on anything because your not going to be living there. so its make up an excuse not to spend the money. "northlands warm so we don't need insulation in southland" kind of nonsense.

had that crap back in the 90's, they didn't want insulation but how many people would want a house with out it today?

Handle9

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#3099896 4-Jul-2023 19:33

Insulation has been mandatory since 1978

tweake

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#3099907 4-Jul-2023 20:21

Handle9:

Insulation has been mandatory since 1978

only ceiling insulation. wall insulation wasn't until the 80's afaik. but the point here is that people where still complaining about having to have it 10 years later.

to put it into context, by the 90's ~60% of UK homes had double glazing.

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#3099910 4-Jul-2023 20:29

tweake:

Handle9:

Insulation has been mandatory since 1978

only ceiling insulation. wall insulation wasn't until the 80's afaik. but the point here is that people where still complaining about having to have it 10 years later.

to put it into context, by the 90's ~60% of UK homes had double glazing.

It's a much more hostile climate in much of the UK.

Ceiling, wall and floor insulation were made compulsory in 1978. As the industry in NZ has evolved so have the construction standards.

Continuously bitching about NZ houses and New Zealanders is pointless. The industry is better than it's been and will be better in the future as standards evolve.

tweake

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#3099914 4-Jul-2023 21:05

Handle9:

It's a much more hostile climate in much of the UK.

Ceiling, wall and floor insulation were made compulsory in 1978. As the industry in NZ has evolved so have the construction standards.

Continuously bitching about NZ houses and New Zealanders is pointless. The industry is better than it's been and will be better in the future as standards evolve.

the story i've always heard was ceiling standard came first then the wall insulation later. if that was an enforcement thing, maybe they delayed so industry could catch up, i don't know.

uk/usa are harder climates therefore we don't need to have houses built for our climate is a nonsense argument. the new regs only starts us to catch up. its like not requiring thermally broken double glazing for "cost" reasons (which never happened). the industry is 40 years behind everyone else for equivalent climate.

the point of all this bitching is that people keep making up excuses not to make houses good, with a common excuse being "nz is mild climate" therefore we don't need any. often its the professionals who are the worse for it. some want to get rid of insulation (thinner) to keep the look of the house, or simply cost so they can spend it on another feature. some designs are so bad its a wonder they pass code. some are even calling for scrapping council liability so they can cut corners on building. housing is always a race to the bottom.

if the pro's and clients don't get onboard with it then houses will get built poorly and its everyone else that will suffer from it later on.

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#3099975 4-Jul-2023 21:25

Whatever. We’re way off topic and you’re off in your own world. I guess it gives you something to complain about.

Newtown

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#3099991 4-Jul-2023 22:22

tweake has a point. It's known that the NZ building code isn't up to scratch. This is why we have cold, mouldy, damp houses. MBIE are trying to fix it with the new H1 Energy Efficiency requirements, but have of course had push back from the building industry along the way.

A high performance house, e.g. passive house, is the answer to building a better house that will outperform any modern NZ building. Highly spec:d, doesn't need much energy to run, low power bills, fresh air via ventilation with heat recovery.

To the OP, have you considered putting in a ventilation system with heat recovery? Mitsi got the Lossnay system that can be integrated into a ducted heat pump system.

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#3100021 5-Jul-2023 00:14

Newtown:

tweake has a point. It's known that the NZ building code isn't up to scratch. This is why we have cold, mouldy, damp houses.

The vast majority of "cold, mouldy damp houses" were built prior to the 1978 building code coming into effect. 2/3 of New Zealands houses are older than 20 years old, around half are older than 40 years old. Around 20% of NZ houses are effected by dampness and around 17% have mould problems. Most of those aren't a problem with the building code, they are historical building stock.

A well built house built in the last 20 years isn't cold. It could be built better and double glazing is the obvious thing that was omitted from the code until 2007, but they aren't particularly expensive to heat to a comfortable level. The cost difference to build to a passive house standard doesn't make financial sense in a temperate climate like NZ. The biggest issue with New Zealand building performance in NZ is overall construction costs, not the building code itself.

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#3100036 5-Jul-2023 07:40

I don't understand why NZ is often called "temperate". I find it fairly warm in summer but quite cold in winter.

In winter in Wellington it regularly gets down to almost 0 - 3 degrees overnight, many days don't get over 10 degrees, though we do have quite a few sunny and warm days in winter as well. We have an old but fairly well insulated house, we end up using heating about 7-8 months of the year and cooling 2-3 months of the year. Part of that is poor house design (i.e. it probably wasn't designed), if it was designed better it could avoid so much solar gain in summer and receive more in winter.

Aitchy

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#3100038 5-Jul-2023 07:51

Newtown:

To the OP, have you considered putting in a ventilation system with heat recovery? Mitsi got the Lossnay system that can be integrated into a ducted heat pump system.

Our house is 1950s so not airtight, Lossnay is recommended for modern, airtight homes. We have a positive pressure ventilation system at present. I think ducted might be overkill for our needs as we have a heat pump for kitchen, dining and lounge that is fairly new and does the job at that end of the house. It’s really the cooling in summer we need - norwest days in Chch are brutal.

tweake

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#3100070 5-Jul-2023 09:19

timmmay:

I don't understand why NZ is often called "temperate". I find it fairly warm in summer but quite cold in winter.

In winter in Wellington it regularly gets down to almost 0 - 3 degrees overnight, many days don't get over 10 degrees, though we do have quite a few sunny and warm days in winter as well. We have an old but fairly well insulated house, we end up using heating about 7-8 months of the year and cooling 2-3 months of the year. Part of that is poor house design (i.e. it probably wasn't designed), if it was designed better it could avoid so much solar gain in summer and receive more in winter.

a month or so ago somewhere down south hit -20c, with a high of 0c for a week. i would hate to see their heating bills. yet until last month still building the same spec as what often built in auckland northland (as i mentioned before). but we are temperate mild climate not as harsh as uk, yeah right.

for me in northland i heat for couple of months, but aircon for the rest of the year. there is very few days the heat pumps don't run.

tweake

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#3100074 5-Jul-2023 09:34

Handle9:

Newtown:

tweake has a point. It's known that the NZ building code isn't up to scratch. This is why we have cold, mouldy, damp houses.

The vast majority of "cold, mouldy damp houses" were built prior to the 1978 building code coming into effect. 2/3 of New Zealands houses are older than 20 years old, around half are older than 40 years old. Around 20% of NZ houses are effected by dampness and around 17% have mould problems. Most of those aren't a problem with the building code, they are historical building stock.

A well built house built in the last 20 years isn't cold. It could be built better and double glazing is the obvious thing that was omitted from the code until 2007, but they aren't particularly expensive to heat to a comfortable level. The cost difference to build to a passive house standard doesn't make financial sense in a temperate climate like NZ. The biggest issue with New Zealand building performance in NZ is overall construction costs, not the building code itself.

firstly big difference between northland and southland which only been fixed last month. the previous system of 3 areas was very lame and minimal difference between them. so even new houses can be expensive to heat. also because people are taught not to heat, "because nz is mild", the houses are cold. insulation doesn't make heat.

also allowing non-thermally broken aluminium windows was a major mistake. what was even worse is the code only worked on the glass insulation value no the entire window. so you can get double glazing thats as bad as single glazing.

moldy houses i can't recall age range, but interestingly enough most moldy homes are in auckland/northland. its not an insulation issue, its a humidity issue combined with lack of heating (because its so mild).

the building code wasn't up to scratch. it was never a cost thing despite the claims of the building industry. every builder has had clients blow the budget buying bling. its always been about priorities and warm dry housing wasn't one of them until recently.

sorry for off topic a bit here, but i think its important to understand the situation. if people built good homes our cost of heating would be a lot less, the cost of the heating equipment would also be a lot less, and our enjoyment of homes would be far higher.

AklBen

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#3100194 5-Jul-2023 13:54

I am not a fan of split units being used in bedrooms unless there's a strong need for AC in the summer. The reason? You've got a unit that runs with a fan and quite often the fan gets to the point where the air circulation feels cold (it isn't it's just the sensation of breeze).

As Timmay has alluded to over all of these years it's a process to figure out what works best. I would probably start with getting an outdoor unit that can have multi units added to, but start with one or two units in main areas only. I was very surprised how well our single 7kWh unit was able to push heat throughout the house.

timmmay

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#3100214 5-Jul-2023 13:59

AklBen:

As Timmay has alluded to over all of these years it's a process to figure out what works best. I would probably start with getting an outdoor unit that can have multi units added to, but start with one or two units in main areas only. I was very surprised how well our single 7kWh unit was able to push heat throughout the house.

We had a 9kwh unit in our lounge for years that did a reasonably good job of heating the area, including bedrooms where the heat had to go around two corners to get into the rooms. It took hours, but it worked. We needed oil heaters to keep it warm at night though. It was useless for cooling though, that's partly why we ended up with ducted.

tweake

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#3100220 5-Jul-2023 14:14

AklBen:

I am not a fan of split units being used in bedrooms unless there's a strong need for AC in the summer. The reason? You've got a unit that runs with a fan and quite often the fan gets to the point where the air circulation feels cold (it isn't it's just the sensation of breeze).

As Timmay has alluded to over all of these years it's a process to figure out what works best. I would probably start with getting an outdoor unit that can have multi units added to, but start with one or two units in main areas only. I was very surprised how well our single 7kWh unit was able to push heat throughout the house.

if you have large units in the bedrooms i could see that being a problem due to the fan size. however all the units i have stop the fan pretty regularly to avoid making you feel cold by the moving air.

the other thing i would do is light an incense stick and watch the smoke trail. see where it goes. you may have lots of air leakage in the bedrooms, which could be why the bedrooms heat up so well. the hot air is flowing to the outside via the bedrooms.

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